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Oxygen and wound infection: a study of 500 patients

Randomised trial of 500 colorectal surgery patients: wound infections were 5.2% with 80% oxygen during surgery, 11.2% with 30%. A group finding.

Updated October 20, 2026

A randomised trial published in the New England Journal of Medicine (2000) included 500 patients undergoing colorectal resection. During the operation and for two hours afterwards, half received 80% inspired oxygen and half 30%: surgical wound infections were 5.2% in the first group and 11.2% in the second. Length of hospital stay was similar in the two groups.

The mechanism: oxidation as a bactericidal weapon

Neutrophils use oxygen to produce oxygen radicals with antimicrobial action (oxidative burst).

According to the authors, this is the most important defence against surgical pathogens, and it depends on the partial pressure of oxygen in the tissue.

A protocol in a study is not a program for you.

Two women play tennis on a red-clay court overlooking the sea, with wooden rackets, on a sunny day.

What the study measured

The study concerns oxygen given in the operating theatre and for two hours afterwards. It did not assess exercise, breathing or oxygen saturation in the weeks before surgery: how to prepare is decided by the care team.

Why wound infections matter

A surgical site infection (SSI) can require further treatment and sometimes another operation. In this study, patients given more oxygen had fewer infections, an absolute difference of 6 percentage points.

The Digital Twin and this research

The Digital Twin lines up the data your devices write to your phone, such as steps, heart rate and sleep, and shows you how they change over time. It does not measure oxygen in the tissues and it does not diagnose: this research describes groups of people, not you. These are data to read together with your doctor.

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